Depending on the business case one of the following options should be a valid one. It depends on the infrastructure too. There are a few limitations, variations and difference in concept depending on the requirements, for example if the use case involves only Excel 2003 usage, the process of porting data from Excel to SharePoint concept is called Publishing, where as if its Excel 2007, the process is keyed as Exporting. This difference is because
Excel 2003, out of the box (OOTB) it has the ability to synch 2 way with SharePoint.
Excel 2007, OOTB has the ability to do only 1 way synch. Although Microsoft released a add in to make 2 way synch possible.
In either case once the export/publishing is done the data in SharePoint should be considered as the master data.
1. MS Office Excel 2003 – 2 way synch is possible [Publish to SharePoint]
2. MS Office Excel 2007 – 1 way synch. (with add in 2 way synch is possible) [Export to SharePoint]
http://msdn.microsoft.com/en-us/library/bb462636%28office.11%29.aspx (Addin 2 way synch)
http://office.microsoft.com/en-us/excel/HA101314721033.aspx One way synch (SP to Excel)
4. Publishing Excel Workbooks to SharePoint so that users without MS Office can access complex spreadsheets in Browser